Preheat oven to 350°F. Line a baking sheet with parchment paper. Set aside.
In a small bowl, combine the all-purpose flour, almond flour, and baking powder. Set aside.
1 cup all-purpose flour, ½ cup almond flour, 1 teaspoon baking powder
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar on medium-high speed until light and fluffy, about 2 minutes.
¼ cup unsalted butter, ½ cup granulated sugar
Add the eggs, vanilla extract, and almond extract, if using. Mix on low speed, just until combined.
2 large eggs, 1 teaspoon pure vanilla extract, ¼ teaspoon almond extract
With the mixer on low speed, add the dry ingredients into the wet ingredients slowly. When all of the dry ingredients have been incorporated, add the sliced almonds and chocolate chips. Mix just until they are evenly distributed, about 15 seconds.
¼ cup sliced almonds, ¼ cup mini chocolate chips
Shape the dough into two logs that are about 2 inches wide, ¾ of an inch tall, and 8 inches long.
Bake the biscotti logs for 20-25 minutes, or until they are set and beginning to brown on the edges.
Slice each biscotti log into 8 equal pieces and lay the pieces cut side up on the baking sheet. Be careful-- they’re hot!
Bake the biscotti for an additional 20-25 minutes, or until they are firm and dry. Allow the biscotti to cool fully before transferring them to an airtight container.